Improvement in cutters for removing casings



Patented' Dec. 24, 1872. I

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.1. H. LUTHER & F. STEPHENSN.j

H Il IIL B Cutters for Removi'ng Gasngs frdo'm 01| Wells.

f UNITED STATES JAMES H. LUTHER AND FREDRICK STEPHENSON, OF PETROLEUM CENTRE; SAID STEPHENSON ASSIGNOR .TO PERLEY H. LAYVRENCE, OF LAVRENCE- BURG, PENNSYLVANIA.

IMPROVEMENT EN CUTTERS FOR REMOVING CASSNGS FROM OEL-WELLS.

Specification forming part of Letters Patent No. 134,150, dated December 24, 1872.

To all whom zt may concern:

Be it known that we, JAMES H. LUTHER and FREnRrcK STEPHnNsoN', of Petroleum Centre, in the county of Venango and State of Pennsylvania, have invented a new and useful Improvement in Cutters for Cutting and Removing the Casings of Oil-Wells, and we do hereby declare the following to be afull, clear, and exact description thereof, reference being had to the accompanying drawing making a part of this specication, in which- Figure l is a side view of our improved casing-cutter, and Fig. 2 is a vertical sectional view thereof.

Like letters of reference indicate like parts in each.

In the casing-cutters in use previous tc the date of our invention for cutting and removing the casing from oil-wells, two connections were commonly required from the cutting-tool to the mouth ofthe well-one, the sucker-rod, to force the cutters or knives outwardly against the inside of the casing, and the other, the tubing, to rotate the cutters. l

By our improvement we are enabled to dispense with one of these connections and perform both operations by the use of the other.

To enable others skilled in-the art to make and use our invention, we will proceed t describe its construction and mode of operation.

B is a cylindrical block of a little less diameter than the inner diameter of the casing A which is to be cut. A threaded or screw-stem, b, extends from it upward in its axial line through the tubular stock D, in which the cutters a are set. This stock carries on a seat, d, a loose nut, d', suitably tapped` for the screwcollar b to be screwed therein. This screwcollar b is connected by means of the flanged ring -Bl with the block B. Then, when the block B is screwed up against the lower end of the stock D, the nut d will revolve freely so as to permit of the rotation of the stock D, whilevthe block B remains stationary, as presently to be described. The cutters a may be circular, as shown, or of other known form. They are set in heads a', and these heads play y in and out of the stock D through mortises in the sides. To work them in and out we employ levers c c, pivoted at c', and extending up and passing through guiding-slots e in the nut e. This nut is tapped and the screw-stem b passes through it, so that by being turned thereon it will be screwed up or down. The lever-handles c are bent in such way that as the nut e is screwed down the cutters a will be drawn in, and when up the cutters a will be forced out against the inside of the casing A, or vice versa, it so preferred. A joint-tubing, H, is screwed into the upper end of the stock D, and, by successive joints screwed on, connection is made with the mouth of the well. It will be understood that the direction of the pitch ofthe various screws must be such, relatively, that the devices will not be in danger ot' being screwed apart while in use in the well; and, the better to secure this end, other than screw-joints may be employed. The block B has set in mortises in its cylindrical face a series of hinged lugs, s s, of any suitable construction, such that when the tool described is lowered down the casing such lugs will fall out or may be thrust out against the inner face of the casing, and, taking a secure bite thereon or therein, will prevent the block B from rotatin g. These lugs may be in any desired number, as also the cutters a.

When, as illustrated in the drawing, the lugs s. s are designed to fall out, they should be pivoted or hung in such way that, when not held in, they will fall out by their own gravity 5 and their biting-edge shouldvbe of a cam or eccentrie or other equivalent shape, such that, by raising slightly on the block B, their biting'- edges will be forced into or against the casing sufiicieiitlyto prevent the rotation of the block. When designed to be forced out, any known mechanical means ordinarily employed for kindred purposes may be used for this.

rotation of the stock D, communicating motion by means of the lever-handles c c, causes the In operation, the tool describedis lowered ,e leerme rotation of the nut e. The nut e, being there'- by screwed up, gradually shifts the levers c so as to thrust out the cutter ct against the inside of the casing. In this way the casing is cut, and, when wholly severed, the part cut olf is lifted out by hoisting away at the tubing H.

Instead of the levers and nut for driving out the cutters', other known devices suitable for such purposes may be employed. A screw may be arranged to force up a cone or wedge between the base ends of the heads a',- or a scroll working against the bases of the heads co may be used; or toothed racks and a pinion may be employed. In this respect we do not limit ourselves to any particular devices, provided only they be so connected with the other devices as to be operated by the rotation of the cutter carrier or stock.

The three elements which make up our combinationviz., a non-rotatin g block, a rotating cutter carrier or stock, and an expanding device for thrusting the cutter or cutters outwardly, such device being operated by the rotation of the cutter-carrier--may be varied considerably in their relative arrangement. The stationary block B may be arranged above the stock D instead of below, with a sucker-rod connection through it to the rotating stock and expanding devices. If a screw-stem b be used it may rotate with the stock or cutter carrier, and, by its rotation, drive the cutters outward. These and other variations which, by similar devices and a similar operation7 perform the same function, we include in our invention as a part thereof. Hence,

What we claim, and desire to secure by Let ters Patent, is

1. In a casing-cutter, the combination of a non-rotatin g block, a rotating cutter carrier or stock, and suitable devices for forcing the cutter or cutters outwardly against the casing, when such devices are operated by the rota tion of thc stock7 substantially as set forth.

2. As a part of a casing-cutter7 the block B having lugs s loosely pivoted therein, arranged and operative substantially as set forth.

3. The combination of screw-stem b, nut e, levers c, and cutter-heads ai', substantially as set forth.

In testimony whereof we, the said JAMES H. LUTHER and FREDRICK SrEPHENsoN, have hereunto set our hands.

JAMES H. LUTHER. FREDRIGK STEPHENSON.

Vitnesses:

SAM. REYNOLDS, G. F. LAWRENCE. 

